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Rank 72 of 80

Aachen

9.6 hot days a year, average 2016–2025. In 1951–1960 it was 2.5.

Grid and weather station typically differ by about 0.9 days. If the value is shifted by that much, the city lies on one of the places 67 to 74. How it was checked.

Aachen today has the summers Ludwigshafen am Rhein had in the fifties.

9.6Hot days today
2.5Hot days 1951–1960
16.8hottest year: 1976
70 → 72Rank then and now
23.32026, provisional

2026: 23.3 hot days up to the cut-off date – 2.4 times the decade average. This puts Aachen above its previous record year 1976 (16.8 days). The count covers the first 292 days of the year, up to 19 October. The year is therefore not yet complete, and the figure comes from the daily grid rather than the annual grid, which the DWD only publishes after the end of the year. Over the three most recent years available in both, the two agree on average (+0.18 days); for a single city they typically differ by 1.5 days, in individual cases by up to 6.8. This figure is not included in any decade average or any rank on this page.

010203040195119882025
010203040195119882025
1951–2025, axis 0 to 46 days. Grey: the national median. The same axis as on every other city page – the lines can be compared with one another.

Decade by decade

PeriodHot daysRank
1951–19602.570
1961–19702.870
1971–19803.869
1981–19903.076
1991–20007.362
2001–20107.869
2006–20157.166
2016–20259.672

Context

This figure describes the location of Aachen. No city administration decides on location. On shade over streets, schoolyards and playgrounds, it does.

What can be changed

Location is fixed, the residential surroundings are not

35.3 %of the residential surroundings is tree cover
Rank 44of 80 for green where people live

This measures the share of residential surroundings covered by trees – from the satellite, weighted by the population of the same 100 m cells as the heat figure above. Both figures therefore apply to the same places and can stand side by side. Parks, cemeteries and gardens count. The city’s stock of street trees requires the tree register.

Examples in the same location

Cities with a similar number of hot days and a similar size to Aachen that have clearly more green where people live:

  1. Aachen9.6 days35.3 %
  2. Siegen9.7 days50.2 %
  3. Mülheim an der Ruhr10.9 days49.1 %
  4. Essen10.7 days47.9 %

Hot days per year, average 2016–2025, and green where people live. Compared are cities no more than 1.5 hot days apart, at most three times as large or as small, with at least 5.0 percentage points more green. Green also depends on urban form and topography; the comparison shows what occurs in the same location and is not a grade for any administration.

Heat action plan

A heat action plan is documented for Aachen, but we did not find a published document: it is in progress, announced or adopted. Source: „Aachener Hitzeaktionsplan (AHAP)“.

Research as of 24 October 2026. Corrections and tips to kontakt@julianzuber.de.

The map for this city

For Aachen this has been analysed across the city area: trees, land, heat stress. deutschland-hitzesicher.de/aachen-hitzesicher (in German)

Each city has its own access to its map. Enquiries to kontakt@julianzuber.de.

Neighbours in the ranking

  1. 70Remscheid9.9
  2. 71Siegen9.7
  3. 72Aachen9.6
  4. 73Osnabrück9.5
  5. 74Bremen9.5

Hot days per year, average 2016–2025. All 80 at a glance